Diagnostic Performance of Multiparametric Magnetic Resonance Imaging After Transurethral Resection of Bladder Tumour for Prediction of Muscle Invasion and Detection of Residual Tumour in Non-muscle-invasive Bladder Cancer Patients (SMART-BC)

SMART-BC is a prospective, single-centre clinical investigation evaluating the diagnostic performance of multiparametric magnetic resonance imaging (mpMRI) for detecting residual bladder tumour and predicting muscle invasion in patients with non-muscle-invasive bladder cancer (NMIBC).

The study comprises two work packages. WP1 will include 20 healthy volunteers to optimize the bladder MRI protocol using additional clinical sequences without contrast injection, assessing image quality through quantitative and qualitative metrics. WP2 will enrol up to 66 patients with newly diagnosed bladder lesions and suspicious or high-grade urinary cytology, aiming to obtain 33 evaluable patients who undergo pre- and post-transurethral resection of bladder tumour (TURBT) MRI and repeat TURBT (re-TURBT), when clinically indicated.

In WP2, mpMRI will be performed before initial TURBT and approximately 3-4 weeks afterwards in patients requiring re-TURBT. Diagnostic performance will be assessed using sensitivity, specificity, positive predictive value and negative predictive value, with histopathology as the reference standard. Standard VI-RADS sequences will be compared with an optimized protocol incorporating additional sequences. Secondary objectives include inter-reader agreement, patient-reported comfort and satisfaction, and preliminary evaluation of healthcare costs and the potential to avoid unnecessary re-TURBT procedures. Safety will be assessed through the systematic collection of adverse events, serious adverse events and device deficiencies.

The investigation uses CE-marked 3T MRI systems and follows routine clinical management pathways. Its long-term aim is to determine whether post-TURBT mpMRI can improve diagnostic assessment and support more personalized management of patients with high-risk NMIBC.